:root {
  --paper: #f6f7f9;
  --sheet: #ffffff;
  --ink: #15202b;
  --muted: #5b6776;
  --rule: #dbe1e8;
  --accent: #2752c4;
  --accent-soft: #e7edfb;
  --code-bg: #f1f4f8;
  --ok: #1f7a4d;
  --bad: #b3261e;
  --display: "Source Serif 4", Georgia, serif;
  --body: "Public Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e131a; --sheet: #151c25; --ink: #e3e8ee; --muted: #9aa5b3; --rule: #28323e;
    --accent: #8eaaf5; --accent-soft: #1c2945; --code-bg: #1b2430; --ok: #6fcf9c; --bad: #f08a80;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0e131a; --sheet: #151c25; --ink: #e3e8ee; --muted: #9aa5b3; --rule: #28323e;
  --accent: #8eaaf5; --accent-soft: #1c2945; --code-bg: #1b2430; --ok: #6fcf9c; --bad: #f08a80;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.62 var(--body); }
a { color: var(--accent); text-underline-offset: 2px; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
header.site { border-bottom: 1px solid var(--rule); background: var(--sheet); }
header.site .wrap { display: flex; align-items: center; gap: 24px; min-height: 56px; flex-wrap: wrap; }
.brand { font: 700 19px/1 var(--display); color: var(--ink); text-decoration: none; letter-spacing: .01em; }
nav.top { display: flex; gap: 18px; flex-wrap: wrap; font-size: 15px; }
nav.top a { color: var(--muted); text-decoration: none; }
nav.top a:hover, nav.top a[aria-current] { color: var(--ink); }
main { padding: 32px 0 64px; }
h1, h2, h3 { font-family: var(--display); line-height: 1.25; }
h1 { font-size: 34px; margin: 0 0 12px; }
h2 { font-size: 24px; margin: 36px 0 10px; padding-top: 8px; border-top: 1px solid var(--rule); }
h3 { font-size: 19px; margin: 26px 0 8px; }
.lede { font-size: 19px; color: var(--muted); max-width: 64ch; }
.prose { max-width: 76ch; }
.prose p, .prose li { max-width: 72ch; }
code, pre, textarea { font-family: var(--mono); font-size: 13.5px; }
:not(pre) > code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }
pre { background: var(--code-bg); border: 1px solid var(--rule); border-radius: 8px; padding: 14px 16px; overflow-x: auto; line-height: 1.5; }
table { border-collapse: collapse; width: 100%; margin: 12px 0 18px; font-size: 15px; display: block; overflow-x: auto; }
th, td { text-align: left; vertical-align: top; padding: 7px 10px; border-bottom: 1px solid var(--rule); }
th { font-weight: 600; color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .04em; }
.layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 40px; }
.toc { position: sticky; top: 16px; align-self: start; font-size: 14.5px; }
.toc ol { list-style: none; padding: 0; margin: 0; }
.toc li { margin: 2px 0; }
.toc a { color: var(--muted); text-decoration: none; display: block; padding: 3px 8px; border-radius: 6px; }
.toc a[aria-current] { background: var(--accent-soft); color: var(--ink); }
@media (max-width: 820px) { .layout { grid-template-columns: 1fr; } .toc { position: static; } }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin: 20px 0; }
.card { background: var(--sheet); border: 1px solid var(--rule); border-radius: 10px; padding: 16px 18px; }
.card h3 { margin-top: 0; }
.card p { margin: 6px 0 0; color: var(--muted); font-size: 15px; }
.levels { counter-reset: lvl; list-style: none; padding: 0; }
.levels li { counter-increment: lvl; padding: 8px 0 8px 40px; position: relative; border-bottom: 1px solid var(--rule); }
.levels li::before { content: counter(lvl); position: absolute; left: 0; top: 8px; width: 26px; height: 26px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700; display: grid; place-items: center; font-size: 13px; }
.pill { display: inline-block; font-size: 12.5px; padding: 1px 8px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.play { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 820px) { .play { grid-template-columns: 1fr; } }
.play label { display: block; font-size: 13px; color: var(--muted); font-weight: 600; margin: 0 0 6px; text-transform: uppercase; letter-spacing: .04em; }
.play textarea { width: 100%; min-height: 220px; background: var(--sheet); color: var(--ink); border: 1px solid var(--rule); border-radius: 8px; padding: 12px; line-height: 1.5; resize: vertical; }
.play pre { min-height: 220px; margin: 0; white-space: pre-wrap; word-break: break-word; }
.play .err { color: var(--bad); }
.tabs { display: flex; gap: 6px; margin: 0 0 8px; flex-wrap: wrap; }
.tabs button { font: 600 13px var(--body); border: 1px solid var(--rule); background: var(--sheet); color: var(--muted); padding: 5px 12px; border-radius: 999px; cursor: pointer; }
.tabs button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }
footer.site { border-top: 1px solid var(--rule); color: var(--muted); font-size: 14px; padding: 22px 0 40px; }
.anchor { color: var(--muted); text-decoration: none; opacity: 0; font-weight: 400; margin-left: 4px; }
h2:hover .anchor, h3:hover .anchor, .anchor:focus { opacity: 1; }
.foot { display: flex; flex-wrap: wrap; gap: 10px 32px; align-items: center; justify-content: space-between; }
.steward { display: flex; align-items: center; gap: 10px; }
.it-mark { width: 36px; height: 24px; background: currentColor; -webkit-mask: url(/brand/it-mark.png) center / contain no-repeat; mask: url(/brand/it-mark.png) center / contain no-repeat; color: var(--ink); flex: none; }
.it-line { font-family: "Instrument Sans", var(--body); font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--ink); }
.it-line strong { font-weight: 600; }